A so-called head airbag, also referred to as a curtain airbag or window airbag, unfolds essentially on a vehicle interior in the event of an accident, in order to protect the head and thorax areas of occupants in particular in the event of a side impact or a rollover of the vehicle and to prevent the head of an occupant from projecting outside unprotected through an open side window during the accident.
For example, situating the folded head airbag in a receptacle on the roof of the vehicle for this purpose is known from U.S. Pat. No. 6,276,712 B1 and GB 2 393 154 A. The head airbag is unfolded and thus freed from the receptacle by the filling with a filling gas generated by a gas generator. A gas channel for tensioning the airbag is filled simultaneously with an airbag in U.S. Pat. No. 6,648,368 B2.
A head airbag module having a head airbag and a receptacle, which receives the folded head airbag, is known from US 2006/0208466 A1, gas channels and airbags and/or cells defined by tucks in the head airbag. This head airbag module is implemented so that firstly a horizontal gas channel on the lower edge of the head airbag is filled and a middle part of the head airbag is thus freed from the receptacle. The front and rear airbags are then also freed from the receptacle by filling.
In all known systems, the airbag is thus filled and only completely freed from the receptacle in this way. If the gas supply to the head airbag is interrupted, for example, by the penetration of an obstruction into the vehicle, which damages the gas generator or impairs its communication with the head airbag, this can prevent or delay the complete unfolding of the head airbag.
At least one object of the present invention is to improve a head airbag system according to the species. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.